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Teruhiko Kachi

Bio: Teruhiko Kachi is an academic researcher from Aichi Medical University. The author has contributed to research in topics: Somatosensory evoked potential & Parkinson's disease. The author has an hindex of 21, co-authored 37 publications receiving 2421 citations.

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Journal ArticleDOI
01 May 2002-Brain
TL;DR: The interval from initial symptom to combined motor and autonomic dysfunction can predict functional deterioration and survival in MSA, and the relationship between atrophy and functional status was highly variable among the individuals, suggesting that other factors influenced the functional deterioration.
Abstract: We investigated the disease progression and survival in 230 Japanese patients with multiple system atrophy (MSA; 131 men, 99 women; 208 probable MSA, 22 definite; mean age at onset, 55.4 years). Cerebellar dysfunction (multiple system atrophy-cerebellar; MSA-C) predominated in 155 patients, and parkinsonism (multiple system atrophy-parkinsonian; MSA-P) in 75. The median time from initial symptom to combined motor and autonomic dysfunction was 2 years (range 1-10). Median intervals from onset to aid-requiring walking, confinement to a wheelchair, a bedridden state and death were 3, 5, 8 and 9 years, respectively. Patients manifesting combined motor and autonomic involvement within 3 years of onset had a significantly increased risk of not only developing advanced disease stage but also shorter survival (P < 0.01). MSA-P patients had more rapid functional deterioration than MSA-C patients (aid-requiring walking, P = 0.03; confinement to a wheelchair, P < 0.01; bedridden state, P < 0.01), but showed similar survival. Onset in older individuals showed increased risk of confinement to a wheelchair (P < 0.05), bedridden state (P = 0.03) and death (P < 0.01). Patients initially complaining of motor symptoms had accelerated risk of aid-requiring walking (P < 0.01) and confinement to a wheelchair (P < 0.01) compared with those initially complaining of autonomic symptoms, while the time until confinement to a bedridden state and survival were no worse. Gender was not associated with differences in worsening of function or survival. On MRI, a hyperintense rim at the lateral edge of the dorsolateral putamen was seen in 34.5% of cases, and a 'hot cross bun' sign in the pontine basis (PB) in 63.3%. These putaminal and pontine abnormalities became more prominent as MSA-P and MSA-C features advanced. The atrophy of the cerebellar vermis and PB showed a significant correlation particularly with the interval following the appearance of cerebellar symptoms in MSA-C (r = 0.71, P < 0.01, r = 0.76 and P < 0.01, respectively), but the relationship between atrophy and functional status was highly variable among the individuals, suggesting that other factors influenced the functional deterioration. Atrophy of the corpus callosum was seen in a subpopulation of MSA, suggesting hemispheric involvement in a subgroup of MSA patients. The present study suggested that many factors are involved in the progression of MSA but, most importantly, the interval from initial symptom to combined motor and autonomic dysfunction can predict functional deterioration and survival in MSA.

537 citations

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TL;DR: A large part of the somatosensory homunculus was reproduced quantitatively on an individual brain MRI using magnetoencephalography, which is compatible with the bizarre proportion of the Homunculus with a large tongue, lips, and fingers.

314 citations

Journal ArticleDOI
TL;DR: In patients with Parkinson disease (PD), atrophic changes occur mainly in the limbic/paralimbic and prefrontal areas, which may be related to the development of dementia in PD.
Abstract: Objective Voxel-based morphometry was used to compare the amounts of gray matter in the brains of patients with Parkinson disease (PD) and normal control subjects (NCs) and to identify the specific regions responsible for cognitive dysfunction in PD. Methods Patients were classified into nondemented (ND) and demented (D) groups according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders (4th ed.), and a group comparison was performed. In the ND patients, a correlation was also performed between local gray matter density and the score on Raven Colored Progressive Matrices (RCPM), a test of executive and visuospatial function. Results In patients with advanced ND-PD vs NCs, atrophic changes were observed in the limbic/paralimbic areas and the prefrontal cortex. In D vs ND patients, atrophic change was observed widely in the limbic/paralimbic system, including the anterior cingulate gyrus and hippocampus as well as the temporal lobe, dorsolateral prefrontal cortex, thalamus, and caudate nucleus. The RCPM score was positively correlated with the gray matter density in the dorsolateral prefrontal cortex and the parahippocampal gyrus. Conclusions In patients with Parkinson disease (PD), atrophic changes occur mainly in the limbic/paralimbic and prefrontal areas. These atrophic changes may be related to the development of dementia in PD.

273 citations

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TL;DR: The genetic mutation of X‐linked recessive bulbospinal neuronopathy is amplification of a polymorphic tandem CAG repeat in the androgen receptor gene, which seems to be a determinant factor of clinical severity.
Abstract: The genetic mutation of X-linked recessive bulbospinal neuronopathy is amplification of a polymorphic tandem CAG repeat in the androgen receptor gene. We studied this CAG repeat in 26 Japanese patients from 21 families with X-linked recessive bulbospinal neuronopathy. The number of CAG repeats was significantly correlated with the age at onset of limb muscular weakness (r = -0.596, p < 0.001) and age-adjusted scored disability (r = 0.446, p < 0.03). The length of the CAG repeat therefore seems to be a determinant factor of clinical severity.

200 citations

Journal ArticleDOI
TL;DR: The findings suggest that the disturbed motility in the oral phase of swallowing may be due to bradykinesia, and although PD patients with dysphagia evince a variety of swallowing abnormalities, the duration of pharyngeal swallowing may remain within the age-related range until the symptoms worsen.
Abstract: We studied 16 patients with Parkinson's disease (PD) with dysphagia and 8 young and 7 elderly normal controls videofluorographically to evaluate the nature of swallowing disorders in PD patients. In 13 patients, abnormal findings in the oral phase were residue on the tongue or residue in the anterior and lateral sulci, repeated pumping tongue motion, uncontrolled bolus or premature loss of liquid, and piecemeal deglutition. Thirteen patients showed abnormal findings in the pharyngeal phase, including vallecular residue after swallow, residue in pyriform sinuses, and delayed onset of laryngeal elevation. Ten of these patients also showed abnormal findings in both the oral and pharyngeal phases. Aspiration was seen in 9 patients. The oral transit duration was significantly longer in the patients with and without aspiration than in the control subjects. The stage transition duration, pharyngeal transit duration, duration of the upper esophageal sphincter (UES) opening, and total swallow duration were significantly longer in the patients with and without aspiration than in the young controls, but were not longer than in the elderly controls. These durational changes in the pharyngeal phase of swallowing were similar to those in the elderly controls. The findings suggest that the disturbed motility in the oral phase of swallowing may be due to bradykinesia. Although PD patients with dysphagia evince a variety of swallowing abnormalities, the duration of pharyngeal swallowing may remain within the age-related range until the symptoms worsen.

170 citations


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TL;DR: Clinical diagnostic criteria for probable and possible PD‐D are proposed, characterized by impairment in attention, memory, executive and visuo‐spatial functions, behavioral symptoms such as affective changes, hallucinations, and apathy are frequent.
Abstract: Dementia has been increasingly more recognized to be a common feature in patients with Parkinson's disease (PD), especially in old age. Specific criteria for the clinical diagnosis of dementia associated with PD (PD-D), however, have been lacking. A Task Force, organized by the Movement Disorder Study, was charged with the development of clinical diagnostic criteria for PD-D. The Task Force members were assigned to sub-committees and performed a systematic review of the literature, based on pre-defined selection criteria, in order to identify the epidemiological, clinical, auxillary, and pathological features of PD-D. Clinical diagnostic criteria were then developed based on these findings and group consensus. The incidence of dementia in PD is increased up to six times, point-prevelance is close to 30%, older age and akinetic-rigid form are associated with higher risk. PD-D is characterized by impairment in attention, memory, executive and visuo-spatial functions, behavioral symptoms such as affective changes, hallucinations, and apathy are frequent. There are no specific ancillary investigations for the diagnosis; the main pathological correlate is Lewy body-type degeneration in cerebral cortex and limbic structures. Based on the characteristic features associated with this condition, clinical diagnostic criteria for probable and possible PD-D are proposed.

2,454 citations

Journal ArticleDOI
TL;DR: The utility of structural imaging and other markers will be increased by standardization of acquisition and analysis methods, and by development of robust algorithms for automated assessment, as well as by research into other imaging and nonimaging markers.
Abstract: Structural imaging based on magnetic resonance is an integral part of the clinical assessment of patients with suspected Alzheimer dementia. Prospective data on the natural history of change in structural markers from preclinical to overt stages of Alzheimer disease are radically changing how the disease is conceptualized, and will influence its future diagnosis and treatment. Atrophy of medial temporal structures is now considered to be a valid diagnostic marker at the mild cognitive impairment stage. Structural imaging is also included in diagnostic criteria for the most prevalent non-Alzheimer dementias, reflecting its value in differential diagnosis. In addition, rates of whole-brain and hippocampal atrophy are sensitive markers of neurodegeneration, and are increasingly used as outcome measures in trials of potentially disease-modifying therapies. Large multicenter studies are currently investigating the value of other imaging and nonimaging markers as adjuncts to clinical assessment in diagnosis and monitoring of progression. The utility of structural imaging and other markers will be increased by standardization of acquisition and analysis methods, and by development of robust algorithms for automated assessment.

1,572 citations

Journal ArticleDOI
TL;DR: AIS is an archetypal example of a hormone resistance disorder; however, due to defective androgen receptor (AR1) function, there is loss of target organ response to the hormone, and the effects of androgens are reduced or absent.
Abstract: I. Introduction IN 1953 lohn Morris, an obstetrician at Yale University, reported a series of 82 individuals (80 cases collated from the literature and two cases of his own) who had a female phenotype despite the presence of bilateral testes (1). Since his initial description, studies of the endocrinology, pathophysiology, biochemistry, and molecular biology of the androgen insensitivity syndrome (AIS) have provided insights into the role of androgens in male sex differentiation, the mechanisms of androgen action, and aspects of the structure/function relationships of the androgen receptor. AIS is an archetypal example of a hormone resistance disorder. Androgens are secreted by the testes of these 46,XY individuals in normal or increased amounts; however, due to defective androgen receptor (AR1) function, there is loss of target organ response to the hormone, and the effects of androgens are reduced or absent. Clinical disorders of the AR are reported far more commonly than resistance disorders of other m...

1,316 citations

Journal ArticleDOI
TL;DR: It is postulate that this residual AR activity may be sufficient for development of male primary and secondary sex characteristics, but may fall below a threshold level of activity necessary for normal maintenance of motor neuron function.
Abstract: Some transcription factors contain stretches of polyglutamine encoded by repeats of the trinucleotide CAG. Expansion of the CAG repeat in the androgen receptor (AR) has been correlated with the incidence and severity of X-linked spinal and bulbar muscular atrophy (Kennedy's disease). In order to understand the relationship of this mutation to AR function, we constructed ARs that varied in the position and size of the polyglutamine tract, and assayed for the abilities of these mutant receptors to bind androgen and to activate transcription of several different AR-responsive reporter genes. Elimination of the tract in both human and rat AR resulted in elevated transcriptional activation activity, strongly suggesting that the presence of the polyglutamine tract is inhibitory to transactivation. Progressive expansion of the CAG repeat in human AR caused a linear decrease of transactivation function. Importantly, expansion of the tract did not completely eliminate AR activity. We postulate that this residual AR activity may be sufficient for development of male primary and secondary sex characteristics, but may fall below a threshold level of activity necessary for normal maintenance of motor neuron function. This functional abnormality may be representative of other genetic diseases that are associated with CAG expansion mutations in open reading frames, such as spinocerebellar ataxia type I and Huntington's disease.

1,137 citations